With the continuous development of communication technologies, the requirement on the rate of data transmission is becoming higher and higher. Therefore, the High Speed Downlink Packet Access (HSDPA) technology is introduced in the 3rd Generation Partnership Project (3GPP) R5, and a next generation evolution technology: the Evolved High-Speed Packet Access (HSPA+) is further provided. Compared with HSDPA, HSPA+ introduces two key technologies, one of which is the MIMO technology which is able to multiply the capacity and the spectrum efficiency of communication systems without increasing bandwidths. After the introduction of MIMO, the peak rate of a cell and a single user is 28.8 Mbps in the case of MIMO with 16 QAM, and is 43.2 Mbps in the case of MIMO with 64 QAM.
However, in order to support the MIMO technology, a transmitter needs to modulate data to two independent antennae to be transmitted simultaneously. A receiver also needs to receive the data from two independent antennae at the same time and perform modulation for the data. Therefore, an RNC needs to configure related MIMO parameters for a NodeB and a terminal which transmit and receive data in the MIMO mode, so that both the NodeB and the terminal can process the data according to a specific modulation and demodulation method of the MIMO mode. Thus, normal operation of communication services can be ensured.
With the global popularization of the low carbon concept, people from all walks of life are looking for environment-friendly and energy-saving methods to save energy, to meet the requirement of improving the worsening environment and to overcome the difficulty that natural resource are becoming increasingly scarce. The communication industry is not an exception. The communication industry is actively seeking methods for energy conservation and emission reduction. By saving operation cost, the goal of low carbon operation can be achieved while coping with the fierce competition to increase revenues. However, equipment energy consumption is an important part of operation cost, and thus continuous improvement on equipment energy consumption is the main way to save energy.
FIG. 1 is a structural diagram of a Universal Terrestrial Radio Access Network (UTRAN) system according to the related art. Generally, a NodeB comprises a Base Band Unit (BBU) and a plurality of Radio Units (RU). Therefore it is an appropriate way to save the power consumption of the RUs to save the energy of a base station.
The MIMO needs two sets of RUs, each of which process data on an antenna. Currently, in a Universal Mobile Telecommunications System (UMTS), the advantage of a cell configured in the MIMO mode is the increase of the user data throughput. However, whether a terminal user of the MIMO cell is able to apply a MIMO dual-stream method for scheduling depends on the terminal capability, the data amount of the terminal user and the Channel Quality Indicator (CQI) of the terminal user. The power consumption of the RUs will be wasted if the terminal user still applies in the MIMO mode for transmission in the case that the MIMO mode cannot be adopted.
Therefore, in order to make judgment of the current communication environment rapidly, so that operations can be implemented when energy-saving conditions are satisfied to reduce energy consumption to the greatest extent, the NodeB needs to control the opening/closing of one of the RUs self-adaptively. That is the self-adaptively control of the opening/closing of one of the antennae which is usually an auxiliary antenna. In other words, the NodeB needs to control the MIMO mode switching of the cell. When there are not many User Equipments (UE) which need to communicate in the MIMO mode, or communication does not need to be performed in the MIMO mode because the traffic is low in the current cell, the cell can be switched from the MIMO mode to a non-MIMO mode. Conversely, the cell can be also switched from a non-MIMO mode to the MIMO mode.
A Control RNC (CRNC) is configured to control radio resource of a cell, specifically comprising configuration information, resource status, and radio link management etc. of a cell which belongs to the NodeB.
However, when the NodeB adjusts the MIMO mode of a cell self-adaptively, the CRNC can no longer update the MIMO mode status of the cell managed by the NodeB. This will result in inconsistent use of the current MIMO resource by the NodeB, and the UE will fail to demodulate downlink data of the NodeB. Thus communication cannot be performed normally.